PACAP and a VPAC1 agonist (but not a VPAC2 agonist) also prevented MPTP-induced microglial activation and dopaminergic neuronal degeneration with a potency similar to VIP, suggesting that the protective actions of these neuropeptides are primarily mediated by VPAC1 in this model of PD [141]. The gene discussed is VIPR1; the disease is Parkinson disease.